Saturday, May 28, 2016

A few hidden art works

kw: natural history, museums, photographs, art

When you get behind the scenes at any museum you never know what you'll run across. I was delivering some empty egg cartons to the Education Department at the Delaware Museum of Natural History. They are used for craft projects. I purposely went by the section which houses several tarantulas and other large leggy critters, but they were all asleep or in hiding. I'll have to find out when feeding time is, when they'll be out and active.

Right around the corner this quilt was set up for display, but not in an area that the public usually sees. It is titled Lilypad Mural and the squares are about 9 inches (23 cm).

Later, among the mollusks, I decided to re-photograph some "shell art" that is stored on a low cabinet right in the middle of the mollusk research cabinet room. Of the two pointy balls, the larger one is made from 50,000 auger shells. Among the seven pieces of shell art there is also a carving of a pelican. From the shape and the semi-unfinished stump below, I can see that it was carved from a three-way branch junction.

I enjoy finding all the different ways people make art out of nearly everything!

Sunday, May 22, 2016

The birds that live among us

kw: book reviews, nonfiction, natural history, birds, suburbs

I remember as a child living near the shore of Lake Erie, the morning chorus of birdsong that woke me in the spring and early summer. I taped it once, and I wish I had kept the tape. There seemed so many birds of so many different kinds…

I may have inflated it in my memory over the years. Some of the places I have lived since, didn't seem to have such a variety of birds. South Dakota, for example, just has fewer species because it is South Dakota, not Alabama. But recently I have been paying attention when I am out in the early mornings. It may be that here in the Mid-Atlantic the number and variety of singing birds is much the same as what I remember from fifty years ago in Ohio. Now I find a book that explores the relationship between bird numbers and diversity as they relate to different levels of urbanization: Welcome to Subirdia: Sharing Our Neighborhoods with Wrens, Robins, Woodpeckers, and Other Wildlife, by John M. Marzluff. A portion of the page space is well spent upon illustrations by Jack DeLap, a gifted natural history illustrator.

In ten chapters the book explores the relationship that different bird species have with our "built landscape". Chapters one through seven gradually paint this picture, primarily about species diversity:

  • In temperate regions, such as most of the United States and Europe, the number of different species is the least in inner cities; it is the greatest in suburbs; and it is somewhere in between in rural and forested areas.
  • In tropical regions, the trend is more linear: The greatest diversity is seen in the forests, the least in cities, intermediate levels are found in the suburbs.

In more absolute terms, the level of bird diversity is quite similar in suburban areas over most of the inhabited Earth. But in tropical forests the diversity is several times greater than in temperate forests. Also, worldwide, cities are bird-poor. In general, five very adaptable species are found wherever humans are: House Sparrows, European Starlings, Mallard Ducks, Canada Geese, and Rock Pigeons. Any place that didn't already have these species present, people brought them there, and they have flourished. So much so, that seeing large flocks of pigeons, frequently called "rats with wings", is a sure sign you are in an inner city.

To my observation, a city center is characterized by pigeons, sparrows, and starlings, while Canada geese and mallards favor the suburbs, which also have sparrows and starlings, but where pigeons are rarely seen. Of these five species, only the starlings and sparrows are truly abundant in forests, while meadows and farmlands tend to have very large flocks of starlings and substantial numbers of Canada geese.

Dr. Marzluff has led groups of students on numerous transects and species counts—these days the hip term is "bioblitz"—to confirm and quantify these effects. American suburbs provide two primary attributes compared to cities and temperate forests:

  • A greatly dissected forest-and-field landscape, with numerous mini-habitats that appeal to quite a variety of bird species. Other species that require large forested tracts avoid suburbs.
  • 55 million Americans spend $3 billion yearly on bird food and suet, and hundreds of millions more on bird feeders, birdhouses, and related equipment.

Several studies have shown that feeding wild birds causes a significant increase in the number of species, and the absolute numbers, of birds in an area. However, the suburbs also harbor a deadly enemy of small birds: millions of house cats, which kill at least two billion birds yearly in the U.S. I wonder, has backyard bird feeding increased the bird population sufficiently to offset the numbers taken by cats?

Of course, not all birds like birdseed or suet. Nor do they like the broken-up landscape of a suburb. Such bird species are "avoiders", and are rarely or never found in suburbs. The "adapters" seem to be tolerant and are about equally abundant in suburban yards and forests, while "exploiters" are more frequently found in the suburbs than elsewhere. But not all suburbs are of equal quality from a bird's perspective.

A friend of ours just bought a newly built home in a 55-Plus community. We saw the place when he asked us to accompany him to inspect it before signing the deed. The whole community is green grass and houses, and all the grass, to my semi-trained eye, is a single species of fescue. There are a few trees planted around the "community building" and other shared facilities. Otherwise, the entire multi-acre property is a green desert to all birds except American robins and starlings, which eat earthworms and yard insects. Fortunately, there are indeed earthworms in this development. I do hope many of the new homeowners will plant multitudes of shrubs and trees and flower beds; then springtime mornings will resound with something more than the robin's "Cheerio" calls.

My neighborhood was developed 60 years ago, and includes a substantial chunk of forest. Every yard has large trees, shrub plantings, flower beds, and various amounts of lawn grass. Off the top of my head, I recall that we frequently see or hear robins, starlings, several kinds of sparrow, chickadees, cardinals, goldfinches, catbirds, mockingbirds, mourning doves, swallows, and tanagers. Less frequently we see a couple kinds of woodpecker, geese (overhead; none have ever landed in our yard), vultures (frequent roadkill squirrels), red-tailed hawks, crows, jays, and orioles. I suspect if I recorded the morning chorus and teased out all the bird calls, there'd be a few more that I haven't yet identified. I am only the most casual of bird watchers.

Chapters 8-10 are more of a call to action. To favor birds in our neighborhoods, we need to foster a greater variety of native shrubs and trees (Azaleas are pretty but don't have much to interest a bird), and grow plants that also favor the birds' favorite insects. Butterfly bush brings adult butterflies, but a variety of spices and herbs are food for many of their caterpillars. A little lawn grass is good, but most yards could do better with less (and you'd spend less for lawnmower fuel!).

Cities can do more also. Every urban area has abandoned and unused land. Some of this can be deliberately planted to favor wildlife. Several instances are described of cities that deliberately increased their "emerald necklace", leading to a more pleasant city for all their residents; the familiar "rails to trails" initiatives are a great example.

As long as Earth's human population numbers in the billions, we will have cities and suburbs. The urban population will most likely double in another generation, even if total population growth slows. So will suburban population, meaning the area occupied by "single family homes" and townhomes and small-scale condo/apartment developments will double in area. With a little forethought, this can benefit wildlife overall, rather than decimate it.

Tuesday, May 17, 2016

The softer side of mollusk studies

kw: natural history, natural science, museums, research, collections, photographs

I have about another week to go for my data-gathering project, and then I'll return to snail inventory. A volunteer showed me another project that is going on. A lot of jars of squids are being sorted and prepared for storage in updated cabinets. This is being done in the "wet lab" because the storage medium for soft specimens is 70% alcohol. The wet lab has the best ventilation, and even then the atmosphere can get a bit heady! The current curator is a squid expert, so the squid collection is slated to grow rapidly.

People don't think of squids when they hear the word Mollusk. If they know the word at all, they think clam or snail. There are about 80,000 species of clams and snails and their nearest relatives (mussels, for example), and most folks have seen many different kinds of seashells. But we seldom encounter squids, other than an occasional bowl of Calamari soup or some chunks of "ika" (the Japanese word) at a sushi bar.

There are squids of all sizes in the oceans, from Architeuthis dux, the 50-foot (15 m) Giant Squid, down to Idiosepius pygmaeus, a bit under a half inch long (~1 cm) when at rest. Measuring a squid is tricky. Being boneless, they are very flexible. The standard measurement is mantle length; the mantle is the squid's "body". The arms can be longer or shorter than the mantle. The two tentacles can stretch to much longer than the arms, but at rest are 2-3 times as long. Thus the largest Giant Squid, or its heavier cousin the Colossal Squid (Mesonychoteuthis hamiltoni), may have a mantle length of 6.5 feet (2 m), with roughly equal arm length, but the tentacles can stretch 35-50 feet (10-15 m), leading to maximum "stretched-out" sizes for these two species of 50-60 feet (18 m).

About 300 squid species are known, but almost every mid-ocean collecting cruise brings back specimens or photos of a new species.

This small jar is about 4 inches high (10 cm), holding a specimen about two inches in mantle length. This is a full grown adult of this species. It is a little smaller than the ones used for Sushi or Calamari soup. Species from this size up to about the size of your arm are the most common, and are a food source for sharks and other predatory (and quick-reacting) fish.
The jar seen just above is at the lower right in this image, next to another specimen of similar size and a jar containing three specimens of a much larger spotted squid. Their mantle length is close to a foot (0.3 m). I didn't read the labels, so I don't know the species of any of these.

Keeping a squid collection is a bit like keeping a caterpillar or spider collection. They don't dry out well so you need to preserve them in alcohol. Many people enjoy collecting seashells or insects, because the shells arrive at the beach already cleaned out and easily dried, and insects dry out readily. But softer-bodied critters are only collected by those who really love the subject. I don't think we have any specimens of squid that somebody just walked in saying, "Hi, I picked this up at the beach the other day and I thought the museum might like to have it." It happens with seashells, all the time. Squids? Not so much. But our curator loves studying these softer, but not necessarily gentler, mollusks (all squids are predators).

Sunday, May 15, 2016

Murder most Fowl

kw: natural history, birds, eggs, predation

A few days ago my wife noticed an eggshell in the driveway. Without much thought, we guessed it was from a hatched robin egg. It is the one on the right. The next day I saw another one, the one on the left. But it wasn't this clean. It had some yolk inside and yolk dripping from the side. I washed it out and off, and sat it next to the other to dry.

We soon recognized that both were victims of predation by a bird. The yellow smears on the first egg, which are sticking some bits of grass to it, are also dried yolk. Robin eggs are frequently punctured and eaten by crows and jays, and several other birds that are secondary predators (primary predators are the raptors such as hawks and eagles). Mammal egg predators take the whole egg, run off with it and crunch it down whole.

It is sad but true that "cute little birds" can be as vicious as any tiger. Except that "vicious", a word derived from "vice", is a human term and applies to humans. Neither tigers nor crows are vicious in the human sense. They kill to eat. They must kill or die. There are birds that more closely fit the term "vicious", such as starlings, which puncture eggs in a nest and drive off the parent birds so they can take over the nest.

So how do you tell when an egg shell you find is from a hatched bird, not a "murdered" one? The hatching chick pecks a girdle most of the way around the shell, then pushes to finish the crack. When you find a half shell with peck marks most of the way around, that is from a normal hatchling. The parent birds usually carry each half in a different direction away from the nest, 20 or 30 yards, maybe farther. This misleads predators as to the location of the nest with its vulnerable hatchlings.

Friday, May 13, 2016

Music distribution - no more "buggy whips"

kw: book reviews, nonfiction, music, digital music, copyright, law enforcement, paradigm shifts

Nearly twenty years ago I was introduced to Limewire by a friend. While he was rabidly downloading all the songs of his favorite bands—and thus committing "music piracy"—I had no interest in anything contemporary. I have little interest in music composed after about 1910. I felt lucky to find digitizations with pretty good quality of very early recordings of Western, Country and Western Swing music, and downloaded a pretty good collection of that. Whatever wasn't already in the public domain at the time, probably is by now.

After a safety lecture I attended a police detective was asked how the police decide which laws to enforce. A major point in the following discussion was that a law cannot be enforced unless the rate of voluntary compliance is at least 85%. In the realm of traffic control, we find that stop signs and stop lights are obeyed at levels exceeding 95%, in most places, anyway; but speed laws are so routinely flouted by so many drivers that the "effective speed limit" is between five and twenty miles above the posted speed. I know that on those sections of I-95 north of Baltimore that are posted 55 MPH, to drive slower than 70 is to risk being rear-ended. I have been driving along there at about 70, and been passed by traffic, including state police vehicles, that must have been going over 80!

What do you do when the majority of folks flout a law? Eventually it is either changed or becomes ignored. This can take time—the "noble experiment" of alcohol Prohibition lasted 13 years—but the result is inevitable. Society will pass through a painful period during which many "pioneers" wind up with figurative arrows stuck in them. Then a shift occurs, and soon enough the law enforcement establishment finds itself with something more pressing to do. Whether the now outdated laws remain on the books becomes moot (Prohibition was an exception: having been enacted by Constitutional Amendment, it had to be similarly repealed).

Prior to about 1960, duplication of musical media was difficult and expensive, so people bought "records": 78's, 45's and 33's. The invention of the cassette tape recorder initiated a low level of "music piracy", and as the machines got better and cheaper, the practice became more widespread. But then 1982 happened. Music went digital, and the first commercial CD was pressed. That same year a friend of mine bought one of the first (and rather costly!) portable CD players, and let me listen to a classical selection with his ear buds (also a rather new product). It was astounding! Compelling audio, completely free of hiss, pops and other artifacts of even the best 33-1/3 RPM platters.

Once anything is in digital form it can be reproduced exactly. Many tape cassette recorders of 1982 were very good, but a copy of a copy of a copy was clearly inferior, and the music industry had very expensive machinery to play master tapes into platter-making machinery that did not degrade the precious master, even after it was used many times. Think about it; how do you make a million copies of an analog (LP) album?

No need to go further. Using analog media degrades the media. Using digital media may also degrade the media, but before it is too far gone, you can make a perfect copy and just keep going. Once audio and then video went digital, it became apparent that the physical medium, the CD and later the DVD, was just the "camel" to carry the musical "cargo". If your cargo is so light you don't need camels any more, then what?

"Then What" is ably and aptly described in How Music Got Free: The End of an Industry, the Turn of the Century, and the Patient Zero of Piracy by Stephen Witt. He chronicles the shift in music distribution over the period from about 1985 to 2005, twenty years that produced a generation that thinks of music as "free", but who revere musical performances and will spend as much to see a concert as football buffs spend to attend a Superbowl.

The invention of digital music recording and playback made the "record" industry obsolete, but the CD industry that replaced it lasted only about as long as Prohibition. While CD's continue to be made, they are a tiny market compared to the distribution of music and video without the "camel". And most of that distribution is free, or nearly so. Stephen Witt's book shows how it happened, following the lives of three significant people, and their associates.

They are like the three jaws of a lathe chuck. Seemingly independent, they worked together, unknowingly, to clamp down on music-as-it-was and replace it with something entirely new.
Jaw 1: MP3 encoding of sound. Protagonist: Karlheinz Brandenburg. Impact: Digital sound files around 1/12 the size of the "source", CD-encoded audio, making audio files practically free, if not legally free.
Jaw 2: The destruction of the "camel". Patsy-then-Protagonist: Doug Morris. Impact: As the richest music promoter, cornered the market on Rap (more than once), led portions of the legal battle against "music piracy", then flopped the entire industry from disc-supported to ad-supported (the YouTube model).
Jaw 3: The mega-pirates who became more capable distributors than "the industry". Protagonist: Dell Glover, one of the few pirates who actually profited from illegal distribution. Impact: His insider position enabled him to release the music from Doug Morris's stable of artists one to three weeks ahead of the official schedule, via an organization called the Scene, partly helmed by "Kali".
The first "cutting tool" of the lathe was the legal establishment, from the Justice Department and FBI in the US to similar agencies worldwide (mainly in the West). Once the well-heeled music industry began to cry foul, they worked for years to pierce the veils shrouding the established pirates. Publicly targeting musical consumers, the "downloaders" backfired, but they eventually caught up with the leaders of the various major pirate networks. Their efforts amounted to nailing the barn door firmly shut after all the horses had fled…and had built new and better barns! The second "cutting tool" was the public, including juries that in a few cases declined to render a guilty verdict, but even more the millions who found it unreasonable to spend as much as a dollar per song to record music. Soon enough, they found a new place to spend the money thus freed up: Mega-concerts, the more extreme the better.

Though the book reads as smoothly as a novel, it is a work of crack journalism. You might either love or hate any of these three men, or their associates. Each played his part (yes, "his"; the number of women involved can be counted on the thumbs of both your feet). The protagonists of Jaw 1 and Jaw 2 got rich; Jaw 3 did well enough until being passed through the meat grinder himself; he escaped with his life, and made peace with life in a new kind of world.

FYI: Under current law in the US, copyrighted work is protected for fifty years after the death of the performer or creator, if a person, or 75 years after the death of the person (or the last person, if a group such as the Beatles) when the copyright is assigned to a corporation. So if your favorite composer or performer died before 1921, no matter who held the copyright, it is now voided, in the US. In some other countries, the term is quite a bit longer.

Tuesday, May 10, 2016

Gleaning from an archaic database

kw: natural history, natural science, museums, research, collections, photographs, indexes

For the past couple of weeks I have set aside the inventory I was doing so I could gather data from the museum's original "database", the ledger books that were used in the 1970's and 1980's. They are the original records for the first 160,000 lots that were added to the collection, or Accessioned, to use a curator's term. As it happens, the other records of Accessions are incomplete: Using them we had been able to assign an Accession Code to less than a quarter of the computerized data records I've been working with. So we decided to "slay the dragon". I am going through these books:

I took this picture just after putting away the two books I was using today (I just noticed that I shelved one of them upside-down). Each book seen here contains about 400 pages. With 40 lines per page, and a full ledger being a two-page spread (equal to one 2-sided sheet), each book can hold about 16,000 records. Six smaller books used the first year or two have about 250 pages and hold up to 10,000 records each.

The books are heavy so if I'm rounding up more then two I bring a rolling cart. The rolling cart, waist-high, is just right for me to use at a standing desk. While doing this data gathering I have been putting my keyboard and mouse on a box atop my desk so I can stand and work. It is a refreshing change.

This is a portion of the right page of a ledger spread. The leftmost column of the spread, located way off the image, holds the catalog numbers for the specimen lots. I am gathering the donor records, and assigning Accession ID's to each group of lots from a donor.

A page like this is slow going. The names of seven donors are visible. I am assuming that the fourth line, referring to G. M. MacCoy, goes with the lines below for the "G. M. MacCoy Collection". I also recognize the names of John E. du Pont, the founder of the museum, and Dan Steger, who donated all his shells at once. Mr. du Pont tended to bring in shells in ones and twos and sometimes hundreds throughout the year. We decided to gather all donations by any particular entity (person, group or organization like another museum), for a particular year, into one Accession. Thus these two items can be gathered with Accession records that I'd already started. But the other names will need new Accession records created for them. The goal is that every lot is associated with an Accession ID.

A page like this, or better yet, several such pages in a row, makes the work go much faster. I can record the first and last catalog number for this set of records, and go to the next Accession. One thing that makes the data gathering tricky is that the people filling out the books tended to do a few pages of a large donation, then one or a few single lot donations, and then return to the big one they were doing. We may use pre-assignment of catalog numbers in the future, but these past records are as they are.

I suppose most people would be very bored doing this kind of work, but I have an odd kind of mind. I am interested in learning about the people whose collections built the museum's collection, and I also pay attention to the collector names. The more familiar we are with all these people the easier other tasks will be, including the inventory work I hope to return to in another week or so.

Sunday, May 08, 2016

Window into a warrior's world

kw: book reviews, nonfiction, navy seals, training, memoirs

There aren't many jobs for which the training, education and other preparation required can take longer than one's subsequent career. Navy SEAL is one of them. In Brandon Webb's case, he was in the Navy four years, doing whatever was needed to move him closer to being assigned to BUD/S, the training program for SEALs, before BUD/S itself took up a lot of another year. At that point he was a SEAL, and spent a year as a helicopter spotter and gunner. Then he was invited to train as a SEAL Sniper, which took up a good chunk of the following year. At age 28, after another active year, he was deployed to Afghanistan, where he took part in the January 2002 raid on Zhawar Kili, the mountain complex to which al-Qaeda had fled after being bombed out of Tora Bora. Not long after that he was assigned to the Training Detachment. In the four years that followed he and a handful of others reworked the program to radically increase the effectiveness of Navy snipers; so much so that the Army sought their help with their own program. During this time he trained Marcus Luttrell, who wrote Lone Survivor, and who credits Webb's training in stealthy stalking with saving his own life. In 2006, at age 32, Webb left the Navy to embark on a fulfilling post-SEAL career that draws heavily on the particular skills and training and experience he received as a SEAL. His explicit SEAL training may have totaled a couple of years, but his time in the Navy can be divided into nearly equal halves: Seven years leading up to his certification as a SEAL Sniper, and the eight years that followed; and 2/3 of that was training the next generation of snipers.

That's a basic outline of what we read in Webb's book The Making of a Navy Seal: My Story of Surviving the Toughest Challenge and Training the Best, written with John David Mann. Usually you might think of such an outline as a spoiler, but read the book. Knowing what is coming doesn't spoil a thing. Re-living it with Webb as he and his co-author practically drag us into his life, that is the real pleasure of reading this book. And for an armchair warrior like me, it has the added bonus that I didn't have to get the bruises or feel the thirst along the way.

It is a comfort knowing that, in spite of this country's quisling leadership, there are still those who train far, far beyond what is possible for most of us, to engage the ruthless and wily enemies that still plague us, and ensure those freedoms that undergird the wonder that is the United States of America.

Thursday, May 05, 2016

Presenting CWWN v04 - The Christian (2)

kw: book summaries, watchman nee, christian ministry

Volume 4 of the Collected Works of Watchman Nee continues his "Meditations on the Book of Revelation" from Volume 3. I am not entirely sure which volume(s) of The Christian these articles appeared in.

The first 80 pages of this volume comprise the meditations of Chapter 1 of Revelation. The rest of the volume, more than 150 pages, cover Chapter 2, the letters to Ephesus, Smyrna, and Pergamos. In later works Watchman Nee wrote about the whole book of Revelation. In The Christian he wrote only about Chapters 1 through 3. He also wrote, quite a bit later, a study of just Chapters 2 and 3 that was published under the title The Orthodoxy of the Church, which presents a much more mature view of the seven letters to the seven churches.

Thus I will do no more than to mention an item or two that indicate his room to grow, from this point in his life as someone not yet 25 years of age. He rightly presents Christ in the heavens as a judge of the churches in Asia and by typological extension, as judge of the churches throughout this age of grace. However, he misses the implication of the girding about the Lord's breast. He calls it the girding of a priest at rest. At rest, there is no girding at all. Girding about the loins in the usual manner is for labor or for fighting. The breast indicates love, and for the Lord to be girded about the breast is to show his loving concern in the midst of judgment.

Nee also, extending a certain word to the messenger of Ephesus (the threat to remove the lampstand) and another to Laodicea (spewing out from his mouth), concluded that God had entirely rejected the church, and that all these messages are meant for individuals, and most particularly, "he who overcomes". Beginning just four or five years later, he more rightly determined that not only the church remains on the earth, but that God's workers for the establishing and edification of churches, the apostles, continue to be raised up. Our word "missionary" is the Latin translation of the Greek word for "apostle". True missionaries are apostles.

It is true that God has rejected those human establishments called "churches", that have so thoroughly deviated from the Biblical pattern that few indeed are those who understand the word "εκκλησία", from which we get such words as "ecclesiastical". It means "those called out". The simple pattern in the New Testament has been encrusted with twenty centuries of tradition and it is all the traditions that God rejects. Gatherings of believers that are more political than spiritual (the majority) have indeed lost the lampstand, and are testimonies not to God and His works but to human glory in religiosity.

Had brother Nee been so unfortunate as to die before 1928 or 1930, his writings would be taken as evidence of someone who threw out the baby with the bathwater. Thankfully, he ministered another two decades and more, and his ministry matured into a balance scarcely achieved by any of the most ardent servants of Christ. Thus I view this volume as a touchstone, a springboard into later ministry as God showed him, more and more clearly, how He works with His people today.

Monday, May 02, 2016

More two-in-one specimens

kw: natural history, natural science, museums, research, collections, photographs

A recent acquisition at the Delaware Museum of Natural History contains loads and loads of fossil mollusk shells and related specimens, presumably of Pliocene age. I am entranced by the species that will grow on a shell. This first image shows a coral that was getting started on the upper spire of a snail shell. The shell is a bit less than 1.5 inches (35 mm or so) across, and the coral polyps were around a quarter inch or less (5-6 mm) across. We can also see at least two small oysters had taken up residence. I suppose they hope that the snail grows faster than they do! But some untoward event killed them all and buried them in fine sand and mud where they remained for several million years.

The next photo is a view of the 3" x 6" box the shell above is in, along with other shells of the same species. All of them had "riders", usually barnacles, though I see one shell to the right with larger oysters upon it.

It is early days for this "collection"; at the moment it is a pile. Sorting is just getting going. Comparing this with photos I've published over the past few weeks, we can answer the question, "What is the difference between a hoard and a collection?" Answer: "The Index". The collection manager and his volunteers are busy sorting like with like, and then he gets to identify them, or in some cases send photos, or the shells themselves, to experts who can identify the harder ones. And there's always the chance that a few shells will stump every expert and possibly lead to the designation and description of a new species!

In addition to mollusk shells, I can see at least one coral specimen and a couple of other items that look suspiciously "non mollusk". Considering that all the natural history museum collections of the world may have, so far, discovered only one-tenth of the existing species…well, this work never ends.